Heretofore, in a semiconductor manufacturing process, corrosive gas is employed for etching or the like in a photoresist process. The photoresist process (photoresist coating, exposure, development, and etching) is repeated several times in the semiconductor manufacturing process. Therefore, a gas supply unit for supplying the corrosive gas as required is employed in the actual semiconductor manufacturing process.
FIG. 15 is one example of a circuit diagram of the gas supply unit.
In the gas supply unit, operation gas and purge gas flow from a left side to a right side of the gas supply unit in the figure. An operation gas supply source 1 is sequentially connected to a regulator 2, a pressure sensor 3, an inlet open/close valve (corresponding to “a first fluid control device” in Claims) 4, a mass flow controller 5, and an outlet open/close valve 6. An outlet port of the outlet open/close valve 6 is connected to a vacuum chamber 7. On the other hand, a purge gas supply source 8 is connected to a purge valve (corresponding to “a second fluid control device” in Claims) 9. An output port of the purge valve 9 is connected to and between the inlet open/close valve 4 and the mass flow controller 5.
FIG. 16 is a side view of a conventional gas supply unit 100 embodying the circuit diagram in FIG. 15.
The conventional gas supply unit 100 has the following configuration. The regulator 2 is fixed on top surfaces of an input block 101 and a flow path block 102 by bolts fastened from above, and an input port of the regulator 2 communicates with the operation gas supply source 1 via the input block 101. The pressure sensor 3 is fixed on top surfaces of the flow path block 102 and a flow path block 103 by bolts fastened from above, and an input port of the pressure sensor 3 communicates with an output port of the regulator 2. The inlet open/close valve 4 is fixed on top surfaces of the flow path block 103 and a flow path block 104 by bolts fastened from above, and an input port of the inlet open/close valve 4 communicates with an output port of the pressure sensor 3. The purge valve 9 is fixed on top surfaces of the flow path block 104, a flow path block 105, and a purge block 108 by bolts fastened from above. An operation gas input port of the purge valve 9 communicates with an output port of the inlet open/close valve 4, and a purge gas input port of the purge valve 9 communicates with the purge gas supply source 8 via the purge block 108. The mass flow controller 5 is fixed on top surfaces of the flow path block 105 and a flow path block 106 by bolts fastened from above, and an input port of the mass flow controller 5 communicates with a common output port of the purge valve 9. The outlet open/close valve 6 is fixed on top surfaces of the flow path block 106 and an output block 107 by bolts fastened from above, and an output port of the outlet open/close valve 6 communicates with the vacuum chamber 7 via the output block 107. The gas supply unit 100 is configured with each device 2 to 9 being fixed by the bolts fastened from above, so that an overall length can be shorter, and the unit 100 can be made compact compared to a case where all the devices 2 to 9 are connected by use of pipes (see Patent Document 1).
Further, the mass flow controller 5 is held in a raised position by the flow path blocks 105 and 106 to create a clearance from an installation surface. In this case, either of the inlet open/close valve 4 or the outlet open/close valve 6, which requires less frequency in replacement, is installed sideways on the flow path blocks 105 and 106 and arranged between the mass flow controller 5 and the installation surface, thereby the overall length of the gas supply unit is further shortened. Such a technique has been already proposed (see Patent Document 2).    Patent Document 1: Japanese Unexamined Patent Publication No. 11 (1999)-159649    Patent Document 2: International Publication No. WO2002/093053